The manufacturers of certain electrical components such as dual in-line package (DIP) integrated circuits customarily ship those components to the users thereof in reusable rigid plastic tubes in order to protect the components during shipping and handling. Each tube may be long enough to hold twenty or more components arranged end to end. The components are retained in each tube by plastic pins passed through the tube walls at the opposite ends of the tube. These pins have a shank which is terminated at one end by a relatively large head. The other end of the shank is shaped to form a laterally compressible enlargement or bulb. The pin is somewhat longer than the tube cross section so that the pin can be inserted through aligned holes in the opposite walls of the tube. Those holes are larger than the pin shank but smaller than the enlargement so that when the pin shank with its enlargement is inserted through the two holes and a forward thrust is applied to the head of the pin, the pin enlargement "snaps" through the hole in the far wall thereby retaining the pin in place.
The OEM or other user that receives the loaded tubes must remove at least one of the pins from each tube before the components can be removed from the tubes. In actual practice, a worker manually pulls out one pin and positions the tube in an automated placement machine. In that machine, the components are caused to slide out of the tube, one by one, through the open end thereof for placement on a printed circuit board. Then, after the tube is empty, it is removed from that machine and the worker pulls out the pin at the other end of the tube so that the tube can be sent back to the component supplier for recycling.
Conventionally, the retaining pins are jacked out of the tube manually using side-cutters or a similar hand tool. The removal procedure involves holding the tube with one hand and, using the other hand, inserting the cutter blades between the pin head and the tube wall, bracketing the pin shank, and with a wrist twisting motion, jacking and pulling the pin away from the tube until the pin enlargement squeezes back through the holes in the tube walls. Once removed, the pins are placed in a container for disposal. More often than not, however, the pins drop to the workbench or floor necessitating cleanup later.
Needless to say, pin removal is a tedious and time-consuming task involving a completely repetitive, two-hand process that contributes to the risk of wrist injury and of cumulative trauma developing in the personnel that service the component placement machines.
While at first glance the problem of pin removal does not appear to be particularly momentous, it should be borne in mind that many millions of components stored in tubes are used each year, requiring removal of millions of pins from those tubes. If it takes only a few seconds to remove each pin in the conventional way, it can readily be seen that hundreds of manhours per year are completely wasted, because pin removal does not add any value whatsoever to the product being built from the components.